The invention is related to absorbent structures or absorbent systems which are useful in personal care such as feminine care napkins, diapers and training pants, wound care dressings and bandages, and adult incontinence products. More particularly, the invention relates to absorbent systems that must manage complex body fluids like menses and blood and that still remain highly conformable to the body of the wearer.
Personal care products typically are made with a top sheet material (also referred to as a cover sheet or liner) an absorbent core and a liquid impervious back sheet. Some may also have a surge layer or other specialized layers between the top sheet and absorbent core.
Such materials, particularly for feminine hygiene product usage, can leak, staining garments and causing constant concern for the wearer. Consumer testing has shown that leakage is the number one concern within the feminine care category. Global consumer market research testing has shown this to be the case in all major regions around the globe.
Currently many other methods are used within the art to attempt to reduce leakage. Examples of product features to reduce leakage include channels to direct fluid longitudinally in the pad, flaps with the intent of creating a physical barrier, topographical features to redirect the fluid, and the like.
There remains a need for a personal care product that reduces leakage in a product by directing the flow of fluid within the pad and locking it up in a way to minimize deformation.
It is an object of the invention to provide an absorbent material which when used in a personal care product can quickly take in fluid, partially retain it in the structure and subsequently transfer it downward away from the user (in the Z-direction). It is a further object of the invention to provide a personal care product in which the product distributes fluid within the structure (in the X-Y plane).
The objects of the invention are achieved by a personal care product having an intake/retention/transfer material. Such materials may be manufactured by a variety of processes traditionally used to prepare stabilized nonwoven webs including coforming, carding, airlaying, needlepunching, wetlaying, hydroentangling etc. The web may be prepared from a variety of fibers and mixtures of fibers including but not limited to synthetic fibers, natural fibers including hydroentangled pulp, mechanically and chemically softened pulp, staple fibers, slivers, meltblown and spunbond fibers, and the like. Airlaying is the preferred manufacturing process and airlaid nonwoven composites are the preferred intake/retention/transfer material.
In a particular embodiment, the intake/retention/transfer material is a heterogeneous composite containing between 5 and 25 weight percent of a superabsorbent or gelling material and having a density from a positive amount to less than 0.17 g/cc. A more particular embodiment contains less than 20 weight percent and a still more particular embodiment contains 15 weight percent or less of a superabsorbent or gelling material.
Another aspect of this invention relates to absorbent articles which contain the class of intake/transfer/retention materials mentioned above along with additional absorbent layers such that the absorption of a menses simulant provides fluid partitioning of from a positive amount to less than 72% of fluid in the intake/transfer/retention composite. Additionally said composite should have retention capacity values greater than 2.7 g/g. A more preferred embodiment has a fluid partitioning of less than 66% in the intake/transfer/retention composite and a retention capacity value greater than 3 g/g.